Impacts of climate change on slow metabolism mammals: An ecophysiological perspective

The particular metabolism of armadillos, anteaters and pangolins may have important consequences for their vulnerability to climate change, which have not been studied so far regarding in its ecophysiological aspects. Studies have emphasized that integrating correlative and mechanistic ecological niche models (ENM) is an efficient strategy to estimate species distribution under climate change as it provides a more complete picture of the species' response than if they were performed separately. We evaluate the vulnerability of three Xenarthrans and one Pholidota (animals from the neotropics and Southeast Asia, respectively), under climate change using an integrative approach. This is the first study that performed an integrative ENM for armadillos, anteaters, and pangolins, including thermal tolerance aspects into the model. For all species, the hours of heat stress in the future were greater than under current conditions, except for the anteater which remained stable. Inside of their thermal refuge, however, they will not be exposed to heat stress. Therefore, it is possible that the semi-fossorial species would spend more time inside their burrows in a warmer scenario, reducing their time and energy spent on reproductivity and foraging activities, for example. The species distributions might expand in the future for all species (increasing 6% to 164%, depending on the species). Considering the thermal pressure imposed by climate change on these animals, the range expansion would not be expected. However, the target species are non-endemic and are currently widely distributed, which normally indicate lower vulnerability to climate change. Despite the projected range expansion, the synergy between the increased heat stress we predicted and other threats such as hunting pressure and habitat loss are also a great concern for the conservation of these unique animals. Therefore, these results imply that even predicting a potential expansion of these species distribution, they need to be monitored because they might experience thermal stress in addition to other pressures from human activities.